Energy-Efficient Routing for Connection-Oriented Traffic in Wireless Ad-hoc Networks

We address the problem of routing connection-oriented traffic in wireless ad-hoc networks with energy efficiency. We outlinethe trade-offs that arise by the flexibility of wireless nodes totransmit at different power levels and define a framework forformulating the problem of session routing from the perspective ofenergy expenditure. A set of heuristics are developed for determiningend-to-end unicast paths with sufficient bandwidth and transceiverresources, in which nodes use local information in order to selecttheir transmission power and bandwidth allocation. We propose a setofmetrics that associate each link transmission with a cost andconsiderboth the cases of plentiful and limited bandwidth resources, thelatter jointly with a set of channel allocation algorithms.Performance is captured by call blocking probability and averageconsumed energy. A detailed simulation model has been developed andused to evaluate the algorithms for a variety of networks

Resilient networking in wireless sensor networks

This report deals with security in wireless sensor networks (WSNs), especially in network layer. Multiple secure routing protocols have been proposed in the literature. However, they often use the cryptography to secure routing functionalities. The cryptography alone is not enough to defend against multiple attacks due to the node compromise. Therefore, we need more algorithmic solutions. In this report, we focus on the behavior of routing protocols to determine which properties make them more resilient to attacks. Our aim is to find some answers to the following questions. Are there any existing protocols, not designed initially for security, but which already contain some inherently resilient properties against attacks under which some portion of the network nodes is compromised? If yes, which specific behaviors are making these protocols more resilient? We propose in this report an overview of security strategies for WSNs in general, including existing attacks and defensive measures. In this report we focus at the network layer in particular, and an analysis of the behavior of four particular routing protocols is provided to determine their inherent resiliency to insider attacks. The protocols considered are: Dynamic Source Routing (DSR), Gradient-Based Routing (GBR), Greedy Forwarding (GF) and Random Walk Routing (RWR)

Routing Session Traffic in Fixed All-Wireless Networks under Energy and Bandwidth Limitations

In this paper we study the effects of limited bandwidthresources in the development of energy-efficient routing algorithmsfor connection-oriented traffic in fixed wireless ad-hoc networks. Afrequency division multiple access scheme is considered, in whichnodes must schedule their transmissions by selecting frequencychannels from a limited set in an interference-free fashion. In ourearlier work, we had developed a set of algorithms for determiningend-to-end unicast paths based on link metrics. We argue that inorderto address the effects of limited frequency resources,such algorithms must be coupled with channel allocation mechanismsfor providing conflict free frequency assignments over selectedroutingpaths. To these ends, we propose a set of link metricsfor selecting candidate routing paths and a set of heuristics forfrequency allocation. We evaluate their performance using ourdetailedsimulation model

Fuzzy based load and energy aware multipath routing for mobile ad hoc networks

Routing is a challenging task in Mobile Ad hoc Networks (MANET) due to their dynamic topology and lack of central administration. As a consequence of un-predictable topology changes of such networks, routing protocols employed need to accurately capture the delay, load, available bandwidth and residual node energy at various locations of the network for effective energy and load balancing. This paper presents a fuzzy logic based scheme that ensures delay, load and energy aware routing to avoid congestion and minimise end-to-end delay in MANETs. In the proposed approach, forwarding delay, average load, available bandwidth and residual battery energy at a mobile node are given as inputs to a fuzzy inference engine to determine the traffic distribution possibility from that node based on the given fuzzy rules. Based on the output from the fuzzy system, traffic is distributed over fail-safe multiple routes to reduce the load at a congested node. Through simulation results, we show that our approach reduces end-to-end delay, packet drop and average energy consumption and increases packet delivery ratio for constant bit rate (CBR) traffic when compared with the popular Ad hoc On-demand Multipath Distance Vector (AOMDV) routing protocol